In the middle of; in the center of; surrounded by.
At last the first glimpse from a bridge of an open-top red bus, and a noticeable darkening of the atmosphere from the smoke of London: then the increasingly dingy stations with double-barrel names, set amid what has always been to me the outstanding feature of the "Premier Line" approach to London—the positively marvellous display of crazy chimney-pots on the grey inner suburban houses. As many as twenty, all of varying style, standing together like ranks of jagged teeth, and providing a Dickensian back-cloth which no other route can boast.
The resulting social divisions can seem so "real" and "natural" to those living amid them that there is a strong tendency to believe that they are timeless biological or scientific facts, rather than social facts that have been assembled and built up through human effort.