Hmm, so perhaps you should wait for a couple of years and take them to Wah gardens. The fish ponds there are fascinating for the kids but i am not is a 4 year old will enjoy it that much,
The ponds are so FULL of fish you can just see hundreds of them swimming around. Put some bread on your hand and they will feed from your hand. It is usually fun as far as the kids are concerned.
If the ponds are deep then its a problem, because my four year one at the first sight of water wants to go into it (though we have to bear with his cries when he is told to take a bath). He kept asking me "Pani may jain, pani may jain" at side of Kunhar when others were getting ready for rafting. But still I would take them there to Wagah gardens someday they need to see as much Pakistan as they can at their father's cost .