One of the largest churches in Europe and the largest Gothic church anywhere. Even your kids will be in awe of the tall ceilings and the ornate decoration. When they're done inside, head outside to the couryard filled with bitter orange trees. Next, climb La Giralda, a 35-story bell tower that was originally a minaret. The tower was built with ramps instead of stairs (except for a short staircase near the top) making it possible to visit even with a stroller!
The Cathedral is sometimes closed for ceremonies, so don't save it for your last day in Sevilla.