As with the other villages and settlements on Portland, Chiswell was designated as a conservation area as part of Underhill in 1976, as it is a place of special architectural and historic interest.

[1] Despite its vulnerability to sea storms and flooding Chiswell developed into a thriving community, and by the beginning of the 19th century it had become well established as a "burgeoning centre of trade and exchange".

These are the locally unique way of providing floodways during storm surges and allowing access to small rear building groups as well as the beach.

[5][6] In January 1990 Cyclone Daria hit Chesil Cove and the sea overwhelmed the defensive wall, causing extensive damage and temporarily closing access to and from the mainland.

[7] During January and February 2014 violent storms across southwest England caused more flooding in the village, which received a lot of national and international attention.

[9] The A354 road runs northbound through Chiswell, and at the street's widest point is the village square which now serves as a car parking area.

[2] To the east of the main street is a stretch of open, higher ground acting as a buffer that separates Chiswell from Fortuneswell.