SOLVED. Adult SciFi. People find portal hub on earth. They theoritize that aliens treated earth as maritime turist destination after finding alien yacht. [s]

[Nnjnn]

I remember a scene where a street artist tries to paint surface of alien teleporter and paint doesn't stick to it instead it blinds him and he falls to his death causing outrage. Also one of teleports leads to planet with toxic atmosphere that kills one of researchers.

[Andy]

Jack McDevitt's Ancient Shores, perhaps (starts with discovery of an alien yacht buried deep undergrounds, and eventually leads to a portal network)

Ancient Shores

[Nnjnn]

Thank you, that's it.

[Andy]

Great. Glad to help!