In spite of the above Trevi is one of the most delightful of Umbrian hilltop villages and it's worth some effort to see it. The cathedral is difficult to photograph exceot from a distance but its a great place for walking around and enjoying the squares and the narrow streets. Go into San Francesco church to admire (and if you can to hear) the wall pump organ that claims to be the world's oldest. It has been thoroughly restored quite recently.