Guild Wars 2

When you approach a watchtower, it applies the marked debuff on you.

But, do enemy players see an orange dot on the map even if you are stealth?

Yes but it’s not very accurate. If you try flailing at the dot the player in stealth might not actually be there.

If you stealth, with Marked debuff, the orange dot will appear and stay where you applied stealth at until the stealth runs out.