If you get a chance to visit Italy, I’d highly recommend taking a short train ride from Rome to visit Anzio as well as Nettuno.
The Sicily-Rome American Cemetery in Nettuno is an 8 minute walk from the train station. It’s a very moving place to visit. It was dedicated in 1956 and contains the graves of thousands of American soldiers who lost their lives in Italy during WWII. It has a small museum which documents the Italian campaign of WWII. The cemetery is beautifully kept up with cypress trees, pools, and an incredible map room. The small chapel has some beautiful art including an amazing relief on the ceiling which I’ve included more details about here from the visitor booklet:
The ceiling dome sculpture, 22 feet in diameter, was designed by Gugler,
Kimball & Husted and executed by Paul Manship and by Bruno Bearzi of
Florence. The medieval signs of the Zodiac in high-relief represent the constellations. The planets Mars, Jupiter and Saturn occupy the same relative
positions that they occupied at 0200 hours on January 22, 1944, the historic
moment when the first American and British troops landed on the beaches of Anzio.
After visiting Nettuno, it is a short train ride back to Anzio (Nettuno is the end of the train line). When you debark the train in Anzio if you head down towards the beach, take a 1/2 hour or so to visit the Anzio Beachhead museum which is located in the same building as the archeological museum. This museum contains an amazing area of articles from the WWII campaign including photos of Audie Murphy which are on display. It is a short walk from this museum down to Anzio beach.