I went here in October 2018, and it was incredible. The derelict swimming pool really shows signs of shelling, with aluminum ventilation ripped out of the ceiling and hanging in shreds.
On the cheery side, the Kupari Bay is perfectly beautiful to swim and, and indeed on a sunny day you are likely to find a handful of locals bathing with a striking view of the surrounding ruins.
For reference, uber is easily available in Dubrovnik, and a car from the City Center to Kupari was less than $15 USD, for a ~15 minute ride.
Renovate, add to hotel chain or indie or turn into condoes, apts.
B&B Inn, TV & Movie shooting, photo shoots, storage, archieve.
Still reusable & as Musuem for time serving military.