There are several places for the day tour in Kathmandu valley. There are seven UNESCO world heritage sites in Kathmandu valley from out of Ten world heritage sites. If you have limited time for Nepal and Looking for a half-day tour, full day Tour and 2- three days cultural tours in Kathmandu This article may help you. Usually, a half-day tour can be done single heritage site or Two sites according to your choice. To visit more than Two places, you need to have a full-day tour. The full-day tour includes Kathmandu durbar square, Swyambhumath Temple(Monkey Temple), Bauddhanath Temple, and Pashupatinath Temple or Pathan Durbar square, Bhaktapur Durbar square, and Changu Narayan Temple.
Rather than the world heritage sites, there are some other sites also are in Kathmandu valley and close to Kathmandu. Dakshinkali and Pharping are the other destinations for a day tour from Kathmandu. You may also do Bungmati Khokana od village tour in one day. You can see the typical Newari lifestyle in these villages.
Bouddhanath stupa (A touring site in Kathmandu)