Where do lowestlying cities occur?

Lowest lying cities on Earth are found either along river deltas or surrounded by high cliffs.

Here are few famous examples:

New Orleans- Delta (coastal plain of Missippi River), USA

Venice- Lagoons formed by river Po, Adriatic sea, Italy

Bangkok- Coastal lowland of Chao Phraya River, Thailand

Jakarta (North)- Coast near Delta of Ciliwung river, Indonesia.