If playing on a customized 7.4 server with Tiquanda or Ankrahmun, these areas offer massive mob density. Survival Essentials
Explore the deeper levels for Rotworms and Orcs. Tibia 7.4 Knight Leveling Guide
Good experience, but watch out for the fire elementals and scout groups. Level 40 to 60: The Guard Grind If playing on a customized 7
At this level, you transition from a solo grinder to a vital team member. Tibia 7.4 Knight Leveling Guide
In version 7.4, your level matters far less than your skills. A Level 20 Knight with 70/70 skills will outperform a Level 50 Knight with 50/50 skills every time.
Usually done with a Druid or Sorcerer. You take the hits; they provide the damage. This is the fastest way to level.