Reddit user Ran0702 overlaid the map of Zaralek Cavern, the new Patch 10.1 zone, over the Dragon Isles, to give a sense of how large it is.

Zaralek Cavern can be entered from 3 different locations:

Teerakai Entrance — Located in Ohn’ahran Plains.

Three Falls Entrance — Located in the Azure Span.

Cascade Falls Entrance — Located between Valdrakken and Ohn’ahran Plains.

The zone is slightly larger than Korthia (Shadowlands zone).

Source: Reddit