Saint Petersburg has so many interesting and historical buildings and objects that you need several days to see them all.

 

If you do not have that much time, or want a first glance, an organized city tour with the highlights is a good option.

 

Things to see are the Rostral Columns in front of the old  stock exchange on the spit of  Vasilyevsky Island.

 

The Saint Isaac Cathedral, the Savior on the Spilled Blood and the Smolny Cathedral are fine examples of Russion Orthodox churches.

 

On the immensePalace Square you can admire the red granite Alexander  Column and have a look at the Hermitage to the north and the General Staff buildings with the huge triumphal arch that leads to the city's main street Nevsky Prospect.

 

Other sights are the Kazan Cathedral, the Bronze Horseman,  the historic cruiser Aurora and many many more.

 

We did a too short citytour in AUgust 2016.