INSTA -Συμβουλευτικές Υπηρεσίες - Main Component You are here: Home Projects POSEIDONION GRAND HOTEL POSEIDONION GRAND HOTEL POSEIDONION GRAND HOTEL MEP DESIGN AND SUPERVISION FOR THE POSEIDONION GRAND HOTEL RENOVATION PROJECT “ΠΟΣΕΙΔΩΝΙΟ” IN SPETSES POSEIDONION GRAND HOTEL MEP DESIGN AND SUPERVISION FOR THE POSEIDONION GRAND HOTEL RENOVATION PROJECT “ΠΟΣΕΙΔΩΝΙΟ” IN SPETSES