Immediately after you land at Tribhuban International airport(the only international airport in Nepal) you will be welcomed by airport officials or the representative from your hotel or the travel agency with some beautiful garlands. If you are alone travelling to Kathmandu without assistance of authentic local representative then there will be airport porters and taxidrivers harrshing you right after you get out of airport arrival gate. They will be pulling your bags requesting you to go with any one of them. You should be aware and tell them that you are already booked. Slowly call a driver lining infront of you then he will make things go easy.
Kathmandu is well known for its diverse traditional culture is literally called city of temple. Once you are in Kathmandu do not miss the places like Boudhanath Stupa, Swayambhunath, Thamel, Pashupatinath Temple, Kathmandu Durbar Square, Kopan Monastery, Dakshinkali Temple, Old Freak Street, National Museum of Nepal, Natural History Museum of Nepal, Patan Durbar Square, Bhaktapur Durbar Square, Changu Narayan, Garden of Dreams, Narayanhiti Palace, Hanuman Dhoka, Central Zoo, Nyatapola, Patan Museum, Chandragiri Cable Car, Budhanilkantha Temple, Krishna Mandir and Golden Temple.
We being a professional tourist expert of Nepal have some sincere suggestion which could be useful while travelling to Nepal. First of all be aware if you wish to enjoy the right life in Thamel. There are numerous complaints of harassment in dance bars of Nepal. The girls are beautiful but most of them will cheat tourist. Use one authentic people whom you can trust to guide you through night life of Kathmandu. Never attempt to drink or eat in small cave like hotels. The foods are always contaminated and drinks are like poison. Always select a travel company with good reputation and experiences. Do not go to the mountains alone since death can surround you anytime.