Not far from the main Lopud village, on island of Lopud immerges very nice Franciscan Monastery dating from 1483.
Church is called St. Marie of Špilice. Its fortress dates from 1599 and fortification from 1516.
The main alatar hosts wooden statue of Virgin Mary. Venetian painter Pietro di Giovanni did his polyptych of the Virgin with saints.
Monastery hosts a great work of Nikola Božidarević - the most remarkable name of the "Dubrovnik school".
Check here for more details (in Croatian).
Just right at the sea, stunning location of this church makes for a direct sea access.
Garden in front of the church make for a nice post ceremony gathering with splendid views and shadow. The itinerary may be continued in different directions: a wedding reception directly on island of Lopud where a good restaurant may be found within 10 minutes of walk (great choices of fresh fish). You may head for some other nearby island such as and have a wedding reception on island of Kolocep or island of Sipan which is also not far. Further option is to return to the town of Dubrovnik (about one very enjoyable ride with views) and have your dinner receptions there.
You may base all your wedding events on island of Lopud, the island of Lopud is worth at least 3 days stay (one of the nicest beaches in Croatia) and it is very reasonable priced especially out of peak season. Besides that, it is a good base for day trips in all directions (islands, coast, Dubrovnik) and explore the area further.