The Nepalese city is a location featured in Among Thieves. Although the city is located in Nepal, its exact name is unknown. It is located in an area called the "Valley of Temples"
When Marco Polo first discovered the valley on his travels to find Shambhala, the valley was occupied only by the hundreds of temples. On Marco Polo's map, found by Nathan Drake in Borneo, he describes, in Latin, the sheer scale of his find and its place in the search for Shambhala.
The "Golden Passport" Marco speaks of is the Tibetan Phurba which Marco Polo included with the map. The dagger is for, as Drake describes, "destroying obstacles... y'know, spiritual ones". The markings on the Phurba dagger correspond to symbols found on the temples themselves, and by following the correct symbol, Nathan Drake was able to find the correct temple which concealed the "secret path to Shambhala".
In Among Thieves, Nathan Drake traveled to the Valley of Temples in Nepal, looking for a certain temple related to the Phurba. The temple was thought to house the location of Shambhala and the Cintamani Stone. After fighting their way through the city, Nathan Drake and Chloe Frazer arrived at the hotel, which according to Chloe was the highest building for miles. The hotel was filled with guards however, and they did their fair share of fighting on their way up. When they took the elevator, it got jammed and Chloe was trapped inside. Drake then had to find the control room and turn the power back on.
Once they reached the top, they spotted the temple they are looking for. They also spotted a helicopter coming towards them. The helicopter attempted to kill them both as they found a way to get out of the hotel. During "They're Coming With Us" to "Only One Way Out", Nathan Drake and Chloe Frazer explore the temple in order to find the Cintamani Stone, or at least some clues to where it is. After enduring puzzles and traps, they discover the location. They had to fight their way through Zoran Lazarević's soldiers to get out of the temple.
After Nate, Chloe Frazer, Elena Fisher, and Elena's cameraman Jeff were ambushed by Lazarević's soldiers, Nate and Elena made their way to a rail yard, where Lazarevic and Flynn were holding Chloe. With Elena's help, Nate boarded Lazarevic's train en route to the Himalayas.
The modern day city was built around the many temples and by the events witnessed in Among Thieves it appears the population of the city had been "on the brink of civil war for years". Lazarević aggravated the situation in order to cover his search for the secret path. During the ensuing street battles much of the city was destroyed and many temples laid to ruin.
The hotel is extremely tall and joined to another building at least halfway up by a small bridge. There does not appear to be anyone staying in the hotel however, so it may have fallen into despair. The hotel contains an elevator and stairs and a swimming pool on the roof. The name of the hotel is seen on one of the walls.
Outside the main building is a courtyard-like area, surrounded by buildings and the odd vegetation. When first entering the temple, it appears grand; the walls are a rich gold and red and a large statue lies in the main room. Underneath are damp and dirty tunnels and a deadly trap. The trap is a ceiling covered in spikes that slowly descends, threatening to kill any trespassers. It can only be stopped by destroying the cogs that make it turn. The last room is huge and grand; beams of light shoot around the room using mirrors, and a giant Phurba dagger can be seen hanging from the roof. Underneath this room, at the very heart of the temple, is a complex map pinpointing the location of Shambhala.
The trainyard is a large open space except for the main building in the middle. Inside this building are train parts, train carriages and plenty of stuff to climb about on. One of the train carriages speeds out of the building after the brake is turned off, and the carriage overturns in a deafening screeching sound. Outside are a few trains, train tracks twisting around here and there and many smaller buildings, including a water tower.
The multiplayer maps "The Plaza", "The Temple", and "The Highrise" are each respectively based on the city, the temple, and the hotel areas. The city also appears as a Co-op Objective mission in Nepal Warzone.