Capuchin Crypt Border adds structure to a Trevi itinerary by giving families something more focused than simply seeing the fountain and browsing shops. This area is especially strong for Baroque palaces, underground water history, art galleries, churches, and surprising architectural details. Younger children may need shorter visit lengths, but underground spaces, dramatic rooms, fountains, and visual stories can still hold their attention; older kids and teenagers often get more from the historical and artistic context. For FunDay-style planning, this type of stop is useful because it anchors the route and protects the schedule from heat or rain. It should usually be balanced with gelato, a piazza pause, a shop, or a short outdoor walk so the day does not become too formal. Its best role is adding depth while preserving Trevi’s lively pace.