National Library
established in 1957
If you are a book fan it might be worthwhile to visit as the library contains more than 77000 books, but be clear there is no comfort available for you.
Located in the old palatial Harihar Bhavan, Pulchowk. You can reach it easy by bus. Microbus and Tuk tuk Parking space is also available. It opens in the summer season from 9A.M. to 5PM except on Sunday and Saturday and in winter season it is open from 9A.M. to 4 A.M.
It is the largest library in Nepal and contains books on an extremely wide diversity of subjects, Although most of the books are in English, books in Nepali, Sanskrit, Hindi and Newari are also in the collection. The National Library has even some rare scholarly books in Sanskrit and English dating from 17th century AD.
Even though the books are a real treasure it is a pity that the reading places for adults are ekdam poor. Still there is a nice kid's corner where children can pass their time by reading. And one thing gives hope. The Library is computerizing and is putting its books on the computer screen. With 90% of the work done already the rest will come fast and than you can find any book you want to see and read.

Kaiser Library
established last century but opened to the public in 1968 only
It is worthwhile to visit due to the high number of interesting books even though a visitor will have to take some discomfort is the sitting arrangements are poor
Located in the Kaiser Mahal besides of the Ministry of Education, Thamel it is very easy to reach. The library is a personal collection of a Rana nobility late Field Marshal Kaiser Shumsher Rana. The entire collection is the reflection of personal taste of the late Rana
It opens in the summer season from 9A.M to 5PM except on Saturday, Sunday and public holidays in the winter season it is open from 9AM to 4PM.

The library has a collection of 45,000 books covering history, art, religion, philosophy, law, astrology, etc. The majority of the books are in English language but there are also books in Nepalese, French, Hindi, Newari and Bangali. Still if you want to read in very Old languages even that are possible. So the oldest book in the collection is a Sanskrit manual of 'Tantra', the art of mysticism. This is believed to be at least 1000 years old.

Asa Archives
Established in 1964 and made available to the public in 1987
The place is worthwhile to visit due to its valuable manuscripts and contrary to the other big libraries an attractive environment
It is housed in a private house in a corner of Ason the center of Kathmandu. This library has a collection of around 7000 manuscripts in different languages and over a thousand palm leaf documents.
For visitors with a slight bent on medieval history and religious traditions of Nepal and especially Kathmandu Valley, Asa Archives is probably the best library to visit. A manuscript dated to 1464 AD is considered the oldest manuscript available here. Most of the documents / manuscripts are in Sanskrit or Nepal Bhasa (Newari Script). One also can find specimens of beautiful calligraphy in the collections.
The Asa archives are lucky to have really supportive sponsors between them the Toyota foundation. This has helped to keep Asa Archives managed in modern times, that means with the help of computerization, CD and microfilms. If you are interested to find specific manuscripts its easy
The Archives is open daily except government holidays and Saturdays.