as little or as much as you wish and can sit down to eat anywhere you like, within reason. if you live in the city, then choosing a park is your best bet for enjoying a picnic.
museums are informative, and the right ones can be fun for all the family. many museums have free admission, and you can spend all day hopping from one museum to the next in the city. visiting museums can provide you with a full day of entertainment for a low price, and if you think ahead and take a packed lunch with you, then you can further save on cost. 