Boundaries? Like if its a link to a different mount?

No:

>mkdir foo
>ls -ld foo
drwxr-xr-x 2 alex users 40 Jul  9 10:44 foo/
>mkdir foo/bar
>ls -l foo
total 0
drwxr-xr-x 2 alex users 40 Jul  9 10:44 bar/
>chmod 000 foo
>ls -ld foo
d--------- 3 alex users 60 Jul  9 10:44 foo/
>ls foo
/bin/ls: cannot open directory foo: Permission denied
>cd foo
-bash: cd: foo: Permission denied
>chmod 100 foo
>ls foo
/bin/ls: cannot open directory foo: Permission denied
>cd foo
>pwd
/tmp/foo
>ls
/bin/ls: cannot open directory .: Permission denied
>cd bar
>pwd
/tmp/foo/bar
>cd /tmp
>chmod 400 foo
>ls -ld foo
dr-------- 3 alex users 60 Jul  9 10:44 foo/
>cd foo
-bash: cd: foo: Permission denied
>cd foo/bar
-bash: cd: foo/bar: Permission denied
>
[download]

To read the contents of a directory (/bin/ls, opendir/readdir), you need read permissions, the "r" bit, 4 in the usual octal numbers.

To "cross" the directory, e.g. make it the current directory or just use it in a path, you need execute permissions, the "x" bit, 1 in the usual octal numbers.

Alexander