which和of的对于被修饰词的位置

which和of的对于被修饰词的位置
which和of是被修饰词的修饰成分,如 the old building of the city 和 the old building which was built in 1920,如果要将两个句子放在一起该怎么合成,of在前还是which在前?the old building of the city which was built in 1920 （这种方式虽然读者通顺,但不是说which要紧跟着先行词吗building吗?）还是 the old building which was built in 1920 of the city?（这种虽然貌似对,但读者不通顺） 哪个对呢?这是什么原理一定要说清楚,