Touch WWI with your left hand, WWII with your right

Guam.

The Cormoran is a WWI ship, the Tokai Maru is a WWII ship, which coincidentally were sunk practically touching stern to stern.

You can dive on both these ships, and their sterns are so close togethr that you can touch them simultaneously. Guam is the only place in the world where a WWI wreck and a WWII wreck are in such close proximity.

From wikipedia:
SMS Cormoran
The 290' Cormoran lays in 120 feet of water on her right (starboard) side directly beside the Tokai Maru (which went down in 1943). The easiest way to reach the Cormoran (and dive on two ship from two different wars at the same time) is to follow the midsection hull of the Tokai over the side until you see the Cormoran at 80 feet. The hull of the Cormoran is intact. The engine room is easily accessible through the skylights, and most of the superstructure is relatively intact. Visibility averages 35-40', but can vary due to the tide and large ship traffic in the harbor. A good average diving depth to see all of the port side would be 80-100 feet. Visibility averages 35-40', but can vary due weather and tidal flow in the harbor.

Tokai Maru
The Tokai Maru is a large ship, over 440 feet long. She rests in 120 feet with an 85 degree list to port (left). The shallowest part of the ship is the upper forward bridge area at a depth of 40 feet. A torpedo has blown a hole in the port #3 cargo hold, and this is undoubtedly the torpedo that sunk her. There is damage on the starboard bow, but this is believed to have been inflicted on the first attack in January, 1943. The cargo holds contains remains of truck frames, beds, scrap steel, and misc objects. The engine room is huge, and both of her engines, catwalks, and panels are intact. The after deck house in the stern of the vessel contains at least 4 depth charges, which are plainly visible from the top of the structure. DO NOT attempt to touch or move these depth charges. Visibility averages 35-40', but can vary due to the tide and large ship traffic in the harbor. A good average diving depth to see all of the Tokai would be 60-80 feet.