I shall repeat, the original post DID NOT ASK what seas were below sea level, it was what CITIES!!!
It did say “For extra credit, what other places (besides Death Valley and the Dead Sea) are below sea level?”
So why are people going for the extra credit before answering the main question?
It has been. See posts #4 & 6 above.
Also, thanks to BobT and Colibri for answering my question. 
Because this Board is filled with overachievers?
Risking further junior-mod wrath, a third of the land in Britain’s Broads national park is below sea level.
Yes but that’s only US places.
So, how much of the ocean is below sea level? Or, above? (Not such a stupid question as it may seem.)
Lake Assal, Djibouti, is 512 ft below sea level.
ARRRGHHHH!!! OH NO!!! TOO MUCH INFORMATION!!! :eek: :eek: :eek:
You might as well get used to the fact that on the Straight Dope, you often get more than you asked for. Sometimes much, much more. 
Since you’re not the OP, why are you getting so perturbed about this?
I was curious how sea-level actually got defined…is it the median point of the tide levels? Is it a fixed reference? Is it ideally spherical, or is the earth’s slightly flattened nature taken into account?
Apparantly there is a lot of hand-waving involved with determining sea level:
Large chunks of the older parts of Venice Italy are below sea level now. What used to be ground floors of some buildings are now “extremely wet” basements.
There has to be a lot of hand-waving in sea level because it is not consistent. The Western Pacific/East Asian coast sea level is a few meters higher than the Eastern Pacific/Western North American coast sea level. In Panama, sea level on the Atlantic side is slightly higher than sea level on the Pacific side. This varies over time because in addition to the effects of the rotation of the Earth, wind patterns also play a role.
Sea level in the United States has been determined by using the average of hourly measurements in different places around the country over a 19-year period (due to the cycles in the Moon’s orbit around the Earth).
My bad… other way around. Sea level is slightly higher on the Pacific side due to wind patterns and ocean currents. My apologies, please carry on. :smack:
Rotterdam is below sea level. Depending on the tide Venice is below sea level.
London is below sea level, or at least, over 150 square kms of it is during high tide. And high tides are getting higher - according to historical records of high tide levels the whole south east of England is tilting downwards by 30 cm a century, whilst the north of the country is getting higher.
This is occurring because of a phenomenon called post-glacial rebound whereby those areas that were weighed down by ice during the ice age are bouncing back.