If you are looking for attractions in San Diego to go to with toddlers here are some suggestions that both the adults and kids absolutely love: 

1.  Cabrillo Monument and view from Point Loma:   You can see absolutely breathtaking views of the bay and the history of light house itself is fascinating.  The toddlers will enjoy looking at the museum like display of the captains cabins and the small staircase in the light house.

2.  Legoland:   So much fun for the young kids and adults alike.   There are lot of rides and activities for little ones and the grown-ups will be amused with the wonderful recreation of all the major cities in the country in miniland.   The harbor cruise boat tour is a highlight to end a perfect day.

3.  Wild Animal Park:  Awesome safari like park.  The tram ride is perfect for every one to sit down and watch the animals so close in a natural setting, everyone will be happy.   The last row of each car in the tram has a netted cargo area to put your personal belongings for those carrying sippy cups and milk bottles around - how sweet!  Only thing is the terrain is up hill down hill quite a bit, so a stroller is a must for the little ones as the little feet get tired after you are half way through. Feels like a visit to Africa.

4.  USS Midway - Even though it has a lot of narrow passages and lots of stairways, it is well worth the effort.  No use taking strollers over - better to carry the babies and let the toddlers walk around.  The flight deck is a must see if nothing else, fascinating.   The toddlers will enjoy the engine room too and people who explain various features truly enjoy their work!   The Island tour has height restriction but toddlers will talk about how you get to turn the wheels and look at all things that help navigate the ship!

5.  Balboa Park - Even if you don't have time to go into the museums, the area itself is so beautiful it is just nice to walk around and take some good pictures.  The architecture of the buildings is gorgeous and with all the beautiful plants and fountains, it is very pretty to look at at sunset.

6.  Drive on the bridge to Coronado Island - The bridge is so high and a drive up and down the bridge and around Coronado Island is fantastic even if you don't get out and go around.

7.  Oceanside Pier and the beach - have a nice play area for the kids to play around on the beach even when the water is too cold.  The long wooden pier is a beautiful sight to behold.

8. Mission Bay Park - Great play areas for young children and a fantastic walking path for the entire family.  Close to Sea World and the airport.  Very accessible right off of  Interstate 5.  Excellent place to spend a few hours if you need to let the kids burn some energy outdoors!

9. Birch Aquarium at Scrips - A small aquarium (compared to Sea World) but toddlers will love it. The main exhibit features fish along the Pacific Coast. Toddler friendly viewing. Outside there are tidal pools for toddlers to look up close and touch fish. The view is amazing. Price is reasonable.

10. SeaWorld - an old favourite keeps getting better! The new Sesame Street Bay of Play is a fantastic adventure land for little ones! They can burn hours here on the climbing apparatus and various play areas. You don't have to be a Sesame Street fan to enjoy this massive play park for kids. 

11. Quail Gardens, Encinitas (20 minutes north of downtown).  It is a delight for kids of all ages and adults.  There are two children's areas where the kids can climb, paint, play with water, clay and other things.  The gardens are divided into geographical areas, such as plants from New Zealand, from South Africa etc.  It pays to purchase an annual pass because it will get you into gardens all over the USA.

12.  The New Children's Museum, San Diego.  This is a really fun place to bring the kids.  The whole museum is kid friendly and is good for toddler's to teens.  The kids can create art projects, paint, play with clay, touch everything and everything in the museum is created by an actual working artist.  Price is reasonable and yearly passes are available.

Overall San Diego is such a fun city for every one and it's weather is just perfect!

also, you can rent equipment from Toddler's Travels - car seats, strollers, highchairs, etc.