Museumdistrict
At just a 5-minute walk, one can find oneself in the museum district. Several of the most popular museums in Utrecht can be found here. Such as:
Central Museum
The Centraal Museum has a sizeable collection of ancient and modern art. The well known Rietveld Schröderhuis (architecture) as well as the Dick Bruna-museum (The Miffy cartoons!) also belong and are part of the Central Museum.
Museum Catharijneconvent
The Catharijneconvent is a national museum for religieus art. Exhibitions display the art within Dutch christianity throughout the ages.
Utrecht University Museum
"At the museum you will experience the differences between science now and in bygone days. Put on a lab coat and carry out experiments or investigate the differences between humans and animals. The Oude Hortus is the old botanical garden of Utrecht. The greenhouses are filled with exotic trees and plants, and is a relaxing place in the middle of the city center, where every season is different!" (excerpt from their website)
Several other museums, in other parts of the city centre, are also within walking distance (10-15 minutes). For instance:
Museum Speelklok
"Museum Speelklok will take you through the wonderful world of self-playing musical instruments, surprising its visitors every day with the cheerful tunes from all corners of the museum. A fun day out in Utrecht for children and adults.
During a visit to the typical Dutch Museum Speelklok, cheerful live music will surround you from centuries-old self-playing musical instruments. The history of these instruments started back in 16th century in the Netherlands with the use of church carillons. Over the centuries, the general desire of people to be surrounded by music, led to the invention of all sorts of self-playing musical instruments: musical clocks, musical boxes, orchestrions (self-playing orchestras) and the traditional Dutch street organs." (source: The Museum Speelklok website)
The Railway museum (Dutch: Spoorwegmuseum)
In this museum, 175 years of Dutch railway history is on display. Many old trains and carriages can be looked at up close. There is also a lot of fun stuff tailored to children.
The Utrecht Archives
"Het Utrechts Archief constitutes the memory of the city and the province Utrecht with dozens of kilometers of archives, half a million of photographs, films, pictures and an extensive library. We want to collect the sources of Utrecht’s history with the aim of making them publicly available" (phrases from their website).
Innercity Churches
Utrecht has a high density of churches troughout the city. Many of which can be visited during the so called Kerken kijken-days; special days in sommer during which the main goal is showing the inside of these churches to the general public.