Situated on the banks of the Yamuna River in Agra, India, the Taj Mahal is a white marble mausoleum complex that dates back to the 17th century. It was commissioned by Mughal emperor Shah Jahan in memory of his favorite wife and later became his own resting place, as well. But the structures fame has much more to do with its impressive, historically significant design than the people who are buried there.Its this incredible synthesis that really defines the early modern world, which is a story about contact, says Kishwar Rizvi, a professor of Islamic art and architecture at Yale University. The Taj Mahal references Timurid architecture from Central Asia, it builds on Safavid architectural trends from Iran, as well as craftsmanship from Italy. And its part of the history of Islam in India, building on the funerary tombs that had existed since the 12th century. Its a fabulous example of this historical moment.To learn more about the Taj Mahal, AD chatted with Rizvi and local licensed tour guide BK Jain. Heres everything you need to know.Where is the Taj Mahal located?The Taj Mahal is located in Agra, a city in the northern Indian state of Uttar Pradesh. It sits on the right bank of the Yamuna River, the second-largest tributary of the Ganges, which is an atypical spot for a mausoleum. The Taj Mahal is a very self-aware structure that breaks away from tradition, explains Rizvi. Rather than having the tomb at the center of a garden, its been pushed to the edge, right on the riverfront. The architecture invites a new and different view. You can see it from the other side of the river.When and why was the Taj Mahal built?In 1631, Shah Jahan ordered that the Taj Mahal be built to house the tomb of his beloved wife Mumtaz Mahal. She was the second queen of the emperor, Jain notes. She died when she was delivering her 14th child. There was an excess of bleeding due to complications in the womb. She was not in Agra at that time, and was instead accompanying Shah Jahan to Burhanpur. While she was pregnant, she spent almost a month on the back of an elephant to reach there.According to legend, Mumtaz Mahal requested that Shah Jahan build her a funerary tomb while she was on her deathbed. She said, You have to make some commitments to me, recounts Jain. First, Please do not marry again. This way, you can remember me in the afterlife. Second, Take care of the children. Third, Build a funerary tomb over my grave. This should be a symbol of love. That is the reason for the Taj Mahal.An illustration of Mumtaz Mahal and Shah Jahan.Photo: Dinodia Photo/Getty ImagesRizvi, however, points out another motivation for the Taj Mahals construction. In the 19th century, there were romantic British stories about this being a monument to love, which, yes, it was built for his wife, but he was always going to be buried there too, she explains. I think its more important to see this as an imperial monument that tells us something about the ambitions of Shah Jahan himself and the worlds that he wanted to create.The mausoleum was completed in 1648, but it was another five years before the rest of the complex was finished. Overall, the project lasted 22 years and required over 20,000 workers. It cost an estimated 32 million rupees at the time, which would be 52.8 billion rupeesor $827 millionnow. These days, you can say its priceless, adds Jain.Who designed the Taj Mahal?Shah Jahan appointed Ustad Ahmad Lahori to lead the team of architects and artisans who designed the Taj Mahal. He was a renowned Persian architect, Jain says. He presented a model to Shah Jahan, who made some modifications and then approved it. The emperor supported Lahori and checked in from time to time.What does the name Taj Mahal mean?The name Taj Mahal is believed to be of Persian origin. Taj means crown and mahal is palace, explains Jain. Its crown palace because the building itself looks like a palace and there are four minarets in the corners, which look like a crown for the building. The real name of the building was Rauza-e-Munawwara, but later on it became known as Taj Mahal.What are the different elements of the Taj Mahal complex?The complex consists of the mausoleum, gardens, and two identical buildings (one a guest house, one a mosque) that create a sense of symmetry.Video: Getty ImagesThe Taj Mahal complex includes a mausoleum, a main gateway, a red sandstone mosque, a jawab (which translates to answer, and looks just like the mosque), and a garden. When you enter the main gate, there is a mosque and an identical building that looks like a mosque, describes Jain. The real name of that second building was Mehmaan Khana, but when the English ruled over India, they called it the guest house. That building just maintains the symmetry. The mosque, the mausoleum, and the guest house are in one line. In the front, theres a beautiful garden with water fountains.What materials were used to build the Taj Mahal?White marble was used to build the Taj Mahal mausoleum, giving it a luminous, ethereal quality. The marble is from a quarry in Makrana, a place in Rajasthan about 240 miles away from Agra, Jain specifies. At the time, there was no modern transportation, so the marble got there by camel carts and burro carts.Shah Jahans choice to employ white marble was also a symbolic one. Sufism, the mystical dimension of Islam, is an integral part of the Indian subcontinent, says Rizvi. The first white domes that we see are on the tombs of Sufi shaikhs. What Shah Jahan is doing in the use of white marble on this tomb is overlaying his authority as the king with his authority as a representative of Islam. He was known to be pious and religious.The mausoleum is located on the banks of the Yamuna River.Photo: Melvyn Longhurst/Getty ImagesThe imported white marble of the mausoleum is juxtaposed with red sandstone from nearby Fatehpur Sikri, which composes the mosque and the guesthouse. I think a beautiful part of the architecture is the balance of red sandstone, which is local, and the gleaming, white marble. opines Rizvi.What are the most important architectural features of the Taj Mahal?The mausoleum building, which stands on a 20-foot tall plinth, is completely symmetrical. Each of its four nearly-identical sides features a pishtaq, a portal with a recessed arch, and an onion-shaped dome. The large, central onion-shaped dome is topped with a finial that was originally gold, but later replaced with gilded bronze.The domes on top of minarets is a unique element of the Taj Mahals architecture.Photo: Philippe Lissac/Getty ImagesFour minarets with small domes on top rise out of the plinths chamfered corners. Usually, you dont see minarets with domes attached to them, explains Rizvi. The mosque on the platform, which is facing towards Mecca, represents an important devotional aspect of the complex. Thus, the Taj Mahal serves both as a tomb, but also as a place where you would go and pray.The gates and the tomb are adorned with calligraphy. From the entrance gateway all the way through, the tomb complex is covered in Quranic verses, almost like a choreographed calligraphic recitation, Rizvi describes. Shah Jahan presented himself as a pious Muslim ruler, in contrast to his father, who was known for his addictions.What are the most important interior design features of the Taj Mahal?The inside of the Taj Mahal is quite different from the outside. The interior is where it flips, its where we see the opulence, shares Rizvi. The exterior is covered in Quranic verses and is very austere, while the interior becomes this almost garden-like space with colorful flora and vegetation. Its a very traditional tomb structure with an octagonal jali, or screen, around it, but its in the details that you get to see some really interesting things.The details Rizvi is alluding to are not frescoes or sculptures, but intricate inlays. From a decoration point of view, there is no paintingthey used only semi-precious stones inlaid into the marble, says Jain. Maybe they thought paint would not be lasting and that is why they introduced this inlay work, which is known as pietra dura in Italian and parchin kari in the Persian language. They used coral, malachite, carnelian, jasper, and lapis lazuli. These gems display that India was the wealthiest nation in the world at the time.Inside, the marble is inlaid with semiprecious stones, such as coral and malachite.Photo: Dinodia Photo/Getty ImagesMany of the inlays depict flowers. The floral motifs show the Mughals interest in naturalism, Rizvi explains. They had been getting botanical books from Europe, brought by the Portuguese and the British envoys and missionaries, so they were very much part of the Mughal vocabulary. For example, you can see poppies that are very realistically rendered.What are the most important features of the Taj Mahal gardens?In front of the mausoleum is a 3,200-square-foot charbagh, also known as a Mughal garden. Inspired by the descriptions of Paradise in the Quran, the garden is divided into four quadrants by two walkways. The idea is like heaven on earth, says Jain. According to the Quran, in front of the house of Allah, theres a beautiful garden with four riversone for hunting, one for milk, one for water, and one for wine. A reflecting pool mirrors the image of the Taj Mahal.Originally, the garden was wild and lush, but it was converted to more tailored, Victorian-style landscaping during the British Raj in India. You have to imagine it as an orchard, which means that there were fruit trees and sweet-smelling flowers like jasmine and rose, Rizvi says. It was meant to be a living, organic space with seasons. It was imagined as a sustaining space of sanctuary. Monuments such as these came with endowments that paid for the buildings care and upkeep, and served as socially responsive institutions. For example, every Thursday, food would be distributed for the poor.How has the Taj Mahal been maintained?Over the years, efforts have been made to protect the Taj Mahal from deterioration. A few decades ago, there were a lot of iron foundries in Agra, but by the order of the law, those were stopped and shifted 50 kilometers away, shares Jain. Right now, the Taj Mahal area is a pollutant-free zone. Vehicles are not allowed up to the Taj Mahal. Before COVID, it was cleaned by a special method. Only the dome was not cleaned. The white part of the mausoleum is totally clean.The Mughal garden was inspired by descriptions of Paradise in the Quran.Photo: Anna Mardo/Getty ImagesDespite these protective measures, the Taj Mahal is still at risk. Marble is very sturdy, but its still an organic material, explains Rizvi. The environment that we have now is not something it can naturally defend itself against, which is why we need conservation scientists and preservationists learning how to protect these buildings from human and environmental damage. And unfortunately, unless they are prioritized, that wont happen. Mughal heritage in India is very much under threat. A lot of my colleagues have been writing and raising alarm about the disrepair of the Taj Mahal. Theres a lot of urgency to its survival.What is the best time to visit the Taj Mahal?A UNESCO World Heritage Site and one of the most popular tourist attractions in the world, the Taj Mahal welcomes over 7 million visitors a year. The best time to tour the Taj Mahal, according to Jain, is from October to March. He advises against coming in January, when its cold and foggy. Most importantly, you shouldnt plan to visit the Taj Mahal on a Friday. The Taj Mahal is closed every Friday for prayer, so tourists are not allowed. Its only for Muslims. Otherwise, its open every day from sunrise to sunset, all year. Just pay the entrance fee, he says.Jain also recommends staying overnight in Agra, rather than just taking a day trip from Delhi, to see landmarks of Mughal architecture like the Agra Fort, the tomb of Itimd-ud-Daulah, and the tomb of Akbar. But, of course, the Taj Mahal will always be the main event. Its a symbol of lovethats why people come here, says Jain. Everyone needs love in his or her life.