Chances are, your guidebook calls Colonia a day trip. And indeed, if you are on a trip with a time limit, you can do plenty here in a day before moving on to the next stop on your journey, and in fact might get restless with more time than that. For us, however, it was an escape from the chaos that is Buenos Aires, and we enjoyed every minute of those three days.
There are a lot of great restaurants in Colonia, so we focused much of our time around picking a place and enjoying our meals. Get away from busy Plaza Mayor and you'll find lots of other options. Try some Uruguayan wines, or medio y medio: half wine, half champagne. (Eh. It tasted fine, but it was sort of just a way to ruin a good wine and/or ruin a good champagne.)
Visit the crafts market! It´s a great place to buy gifts for everyone back home, and a lot of the stuff is similar to what you will find in the craft and souvenir stores, except cheaper. T-shirts, for example, were considerably cheaper at the market. There are so many stalls; you'll probably find something for yourself, too.
We spent one whole morning walking up the beach toward Plaza del Toro. This was when I got sunburned the first time, so watch out. The beaches are lovely, though, and really started to fill up by afternoon when we were on our way back. Aside from the old bullfighting stadium, there's not much up here except houses, but the beach walk was fantastic.
The mall is a short walk away from the old town; we went because we were hoping to catch a movie, but there were only four offerings, and no matinees -- just one, sometimes two, showings of each film per night. The mall is quite small, but it includes a grocery store where we got some fantastic strawberries and a plastic candy cane full of jelly beans.
Having grown accustomed to Buenos Aires, where it seems almost more likely to get hit by a car than not, we were pleasantly surprised to find that cars in Colonia actually stop for pedestrians, even when they have the green light!
We lucked out on finding a place to stay in a guest house. We had no reservations, and were turned away from two posadas before one owner called her friend, who has the guest house. The room was a bit cheaper than the two hotels we stopped by, and it included breakfast and a cool sitting room where we could have watched the sunset if it hadn't been so cloudy. Word to the wise: make reservations, just to be safe. Colonia is a popular weekend getaway. We noticed that on Sunday especially the streets were extra busy.
Brent and I are both people who love to visit new places, but we've already got a soft spot in our hearts for Colonia. I can't wait for the next three day weekend.