- We have a ton of great nature centers (free) that you may also enjoy. My personal favorite is Tamarack Nature Center in White Bear Lake, but that's more for sentimental reasons than anything.
- Also, check out "Universe in the Park," which is a free program put on by the U of MN Astronomy Department. Every Friday/Saturday night they go to a different area park/nature center and give a brief talk about astronomy, and then have 2-3 big telescopes set up where they let you look through them, help you see cool stuff, etc.
- Theodore Wirth Park has some cool features, including a Quaking Bog and a Wildflower Garden
- The Science Museum is phenomenal and definitely worth a visit
- The Minneapolis Institute of Arts is a free museum that is WONDERFUL and definitely worth a visit
- Of course the Walker Art Museum is interesting, although I never go inside because it costs money - my daughter, however, loves going to the Sculpture Garden (free) and then walking across the pedestrian bridge to Loring Park and playing on the playground
- Your younger two would really enjoy the Children's Museum, although that can be expensive and your older child might be bored. However, my nearly 8 year old still loves going there
- The MN Orchestra has free Family Concerts over the summer- you can look into them
- We have among the most wonderfully accessible historical sites, many for really inexpensive. Some of my favorites are:
- Oliver H. Kelley Farm (working 1860's farm, people in costume)
- Fort Snelling (right near the airport)
- MN History Center (Museum in downtown St. Paul - my daughter LOVES it there)
- Jackson St. Roundhouse (open Wed. and Sat, 10-4)
- Mill City Museum (in downtown Mpls - expensive, but well, well worth going)
- Wabasha Sreet Cave Tours
- Dakota City Heritage Village
- Gibbs Farm Museum (working 1890's farm, school house, teepee, and bark lodge, right near the University of MN St. Paul Campus)
- Down in History – coach tours of historical places by people in character
- If you're willing to drive about 45minutes-hour north, the Northwest Company Fur Trading Post is one of my favorite destinations - near Hinckley
If you're just looking for fun (not so much learning) activities, we have
- Valleyfair Amusement Park (insanely expensive, but really fun)
- Como Town rides (next to Como Zoo, which is the free zoo in St. Paul)
- Nickelodean Universe at MOA
Bunker Hills Stable in Coon Rapids has a great trail ride/hay ride thing, and then right across the street from them (almost) is Bunker Beach, which has water slides, a wave pool, a kiddy pool, and a sand play area
- On rainy days, we have lots of indoor play structures. My favorite, though generally the busiest is Edinborough Park in Edina.
One of my favorite summer activities to do with my daughter is to take a paddle boat ride down the river. You catch the boat at Harriet Island in St. Paul.
We also have an inordinate amount of both indoor and outdoor water parks to choose from. My favorite outdoor park is Cascade Water Park in Eagan. We generally make sure we go after 4:00 so we get in for $5/each rather than $10.
A great MN tradition is to go to Lake Harriet and find the elf - leave a message for him.
Other ideas:
-Saint Paul Saints game (baseball)
- Mini-golf
- Foshay Tower
- Midtown Global Market (really fun place to eat lunch with kids because there's food and items from all over the place)
- St. Anthony Lock and Dam
In terms of hotels, unfortunately, I don't have a suggestion for you outside of that I would stay in one of the suburbs rather than the city, because the hotels tend to be cheaper, I think.
I hope you have a great time in St. Paul/Minneapolis!