Most important about Pultusk is that the town is less then 50 km from Warsaw and has less then 20 000 population but you probably know this all already.
Oh and on the way to Warsaw , some 20 km away from Pultusk there is Zalew Zegrzynski
see the pics:
https://www.google.com/search?hl=en&q=zalew+zegrzy%C5%84ski&um=1&ie=UTF-8&sa=N&tab=wi&tbm=isch&gws_rd=sslnice swimming pool in Pultusk, see the town mayor jumping in on opening ceremony: