A very rare visitor to beaches around Auckland is attracting attention, but people are being warned not to get too close.

A large female elephant seal has been spotted in various places around the coastline since yesterday morning.

Usually resident in the sub-Antarctic islands, elephant seals occasionally visit the mainland, but Department of Conservation ranger Thelma Wilson says it's important to keep a respectful and safe distance.

She says elephant seals are big and heavy, but they can move surprisingly quickly.