to be able to look out over; to have a view that reaches across a wide area (can see over/onto something).
山頂から町が一望でき、海も見渡せる。
From the summit you can take in the town at a glance and even see the sea.
このホテルの最上階の部屋は、窓から市街地を見渡せる。
The top-floor rooms of this hotel overlook the city.
展望台からは島全体が見渡せるので、写真を撮る人で混んでいた。
Because you can see the entire island from the observation deck, it was crowded with people taking photos.