"There open fanes and gaping graves..."See in text(Text of the Poem)
The noun “fane” is a shrine, temple, or church. In this disturbing, unnatural city, churches and graves alike “yawn level” with the waves. Everything is so terrifyingly still that one might begin to believe that there are no normal winds “upon some far-off happier sea” elsewhere.
The adjective “pendulous” means hanging, or suspended, and able to swing freely. The shadows are indistinguishable from the buildings, so the entire city appears to be floating in the air without any visible support.
In classical architecture, a “frieze” is the middle of three sections that make up a large structure of moldings called an “entablature,” which is a large structure that sits atop columns. More broadly, however, and in this context, a frieze is an ornamental band on a building or piece of furniture, often sculpted or brought into relief.
A “turret” is a small tower that extends vertically at an angle of a building. Turrets once aided in military fortification, but have more recently been used for decoration.
In this context, the adjective “lurid” contains several meanings: that the sea has a gruesome or horrific quality and/or that it has a yellow to orange—perhaps reddish and fiery—coloring. Though the city in the sea is deprived of heaven’s light from above, it is illuminated by an unnatural, horrible light from below.
The exclamation “Lo!” is a call to look closely or to pay attention to the words that follow, often something the writer considers surprising or amazing. The speaker indicates that the reader should pay close attention to what is about to be described.