One of the best things we've ever done in our house is to convert our fireplace ledge into a city called "Tiny Town." A caveat is that we're not fireplace people and we never use it. My son loves Matchbox cars, but needed somewhere to drive them. So, I got a lot of different colors of posterboard and got to work. Using black and yellow, I made roads. Using blue, a "lake". Using green, a "park". And so on.... To make sure the pieces hold up to serious driving, I cover each one with clear packing tape. My husband's old model train buildings serve as an awesome neighborhood, but you could make your own out of old boxes, legos, etc.
Tiny Town is lovely this time of year....
An aerial view....
In the first versions of Tiny Town, I used masking tape to hold the pieces in place. (Caution - it's possible to get the masking tape residue off, but you need to be prepared to work!). Recently, I've been experimenting with velcro so my little mayor can move things around and rearrange at will. All throughout the "town" are velcro pieces, and also on the back of the various pieces. We're still working out the kinks, but it seems to be a fun option.
I can't even begin to count the number of happy hours my son has spent playing in this part of the house. It's one of my favorite ideas ever, and it costs virtually nothing.