As you've already seen, the coordinates column from the sf_sights table contains a long series of characters that are hardly understandable to humans. As you may remember from Part 2 this is an internal format understood by PostGIS. Luckily, we can make it understandable with the ST_AsText function, which allows us to change the format to Well-Known Text:

SELECT
  name,
  ST_AsText(coordinates)
FROM sf_sights;

The result is quite different than before. Now, in each cell of the coordinates column we have one of three words: point, linestring, or polygon, followed by the list of coordinates in parentheses. Each word signifies a different subtype or simple type of the geometry in question. In this part of the course we will focus on explaining the purpose and usage of each of these subtypes.