It would all depend on where you want to go. If you can be more specific we may be able to help you. However, my recommendation is that before you go anywhere call beforehand and make sure the place you are going to accepts kids. Also depending on age, some places are accepting kids from 12 years old and older.
If you are looking forward to visiting museums check out the list of museums in this link.
Most of the restaurants are not allowed to dine in. Some restaurants are open in pre-booking. You can directly contact the restaurants you want to visit and confirm.
Molten: Your "philosophical" advice is as usual not just hilarious but also raises a question. What if the papa lives with them, which I very much believe he does?
York, We should leave the kids with their papa and do the pending works at the super markets .... etc .... etc ......... yes ......... so they are allowed to go to their papas ............