Ancient monuments are irreplaceable. Unlike a damaged painting that can be restored, a toppled standing stone or an eroded earthwork loses information that can never be recovered. Responsible visiting begins with staying on established paths wherever possible and never climbing on stones, no matter how inviting they appear. The lichen growing on a megalith may be centuries old, and the pressure of hands and feet accelerates its loss.
Many visitors feel drawn to leave offerings — flowers, crystals, candles, coins. While the impulse is understandable, such items can damage stonework, attract animals that burrow into archaeological deposits, and create litter that other visitors must clean up. If you wish to mark your visit, a moment of quiet attention is the most respectful offering you can make.
Finally, remember that these sites exist within living landscapes. Farmers manage the fields around them; local communities depend on tourism income but also bear its costs. Close gates behind you, park considerately, and support local businesses. The goal is to leave each site exactly as you found it — or better — so that the next visitor, and the next generation, can experience the same sense of wonder.