Library of Enlightenment as seen on the adventure map.
Library of enlightenment increases all four primary skills by +2 once for each visiting hero. The hero must be at least at level 10 to receive the bonus. However, with Diplomacy secondary skill, it is possible to acquire the bonus earlier: basic level gives the bonus at level 8, advanced level gives it at level 6, and expert level gives it at level 4.
See also
