How to jump to the start or the end of visual selection in Vim?

Is there a motion for moving to the start or end of a visual selection?

I know that o while in visual mode alternates between the two, but I need to be able to select precisely the start.

The overall goal is to surround a visually selected area with parentheses.

Follow-Up:

Based on the comments, I was able to implement this using the following macro. The idea is to:

1. Esc to exit visual mode;
2. `> to go to the end of the previous visual selection;
3. a) to append a closing parentheses;
4. Esc to exit insert mode;
5. `< to go to the start of the previous visual selection;
6. i( to insert an opening parentheses;
7. Esc to exit insert mode again.

For example:

map \q <ESC>`>a)<ESC>`<i(<ESC>

Based on another comment, we have an even more concise solution:

map \q c()<ESC>P