From the Kathmandu Wikipedia article
Kathmandu is situated in the heart of the Himalaya mountains and has a rich history. Considered by many to be among the most beautiful cities in the world, the earliest known inscription in the Kathmandu Valley is dated 185 AD. The oldest firmly dated building in the earthquake-prone valley is almost 1,992 years old. Four stupas around the city of Patan, said to have been erected by Charumati, attest to the ancient history present within are in Patan near kendra Hiranyavarna Mahavihara (called "Patukodon"). The Licchavi Dynasty whose earliest inscriptions date back to 464 AD were the next rulers of the valley. The Malla Dynasty consisted of Newar rulers, who ruled Kathmandu Valley and the surrounding area from the 12th century till the 17th century, when the Shah Dynasty founder Prithvi Narayan Shah conquered the valley as he created present-day Nepal. Most of ancient Nepali Architecture present in Nepal today is from the Malla/Newar era.The city of Kathmandu is named after a structure in Durbar Square called Kaasthamandap. In Sanskrit, Kaasth (काष्ठ) is "wood" and Mandap (मंडप/मण्डप) is "covered shelter." This unique temple, also known as Maru Sattal, was built in 1596 AD by King Laxmi Narsingh Malla. The entire structure contains no iron nails or supports and is made entirely from wood. Legend has it that the timber used for this two-story pagoda was obtained from a single tree.Kathmandu is also sometimes called "Kantipur". "Kanti" is an alternate name of the Goddess Laxmi, and "pur" means the place where such a goddess resides. Thus, the name Kantipur demonstrates the ancient belief that it is the place where Laxmi dwells.