It's because north of City Hall was the tenement district.

因为市政厅北边是唐楼区。

Thanks to rising land values, we're seeing skyscrapers sprout in what used to be the tenement district like One Manhattan Square on the lower east side and 56th Leonard in Tribeca definitively putting the bedrock myth to bed.

由于地价上涨，我们看到摩天大楼在曾经是公寓楼区的地方拔地而起，例如下东区的曼哈顿广场一号和翠贝卡的伦纳德街 56 号，彻底打破了基岩神话。