sea arch

natural bridge

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Last updated

July 13, 2026

Quick Summary

A natural bridge, also known as a sea arch when formed by wave erosion, is a geological formation that resembles a bridge. These structures are typically created by erosion, often in massive sandstone or limestone rock formations.

Sea arches specifically form along coastlines where waves erode rock. This process can lead to the collapse of the arch, leaving behind a sea stack. Natural bridges can also form from the collapse of a cavern roof or through rivers eroding through meander necks. Notable examples can be found in Utah's Natural Bridges National Monument and Rainbow Bridge National Monument.12

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coastal landforms
Sea arches
Another spectacular type of erosional landform is the sea arch, which forms as the result of different rates of erosion typically due to the varied resistance of bedrock. These archways may have an arcuate or rectangular shape, with the opening extending below water…
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Another spectacular type of erosional landform is the sea arch, which forms as the result of different rates of erosion typically due to the varied resistance of bedrock. These archways may have an arcuate or rectangular shape, with the opening extending below water…
Read More

natural bridge
A related form is the sea arch, produced where remnant headlands may be cut through by waves. Collapse of the bridge portion of a sea arch commonly produces a sea stack.
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A related form is the sea arch, produced where remnant headlands may be cut through by waves. Collapse of the bridge portion of a sea arch commonly produces a sea stack.
Read More