Yes, it really does. Specifically, it looks like the north coastal California mountains in winter (it was really green; but then, everyone was complaining that it'd been raining for 5 weeks), only without so much obscuring vegetation and maybe with more exposed rocks. The hills are about the right height and about the right slope, and have the frequent rock outcroppings that will be familiar to any resident of Napa or Sonoma Counties. The rock, however, is slate. As a national park, Snowdonia is astoundingly beautiful; it's also cold, barren, and remote. It has a few small towns dedicated to the tourist trade, specifically the ski trade; this is one of the places Great Britain goes to ski. It's also where Great Britain goes to climb rocks, but that's a smaller population. Apart from the tourist trade, the only other means of making a living that we saw were sheep farming, and quarrying slate (and what a mess that made!). Snowdonia can also make you feel very small and isolated, stopped at a road pull-out with (as far as I could tell) nothing for about 5 miles in any direction. The day we drove around, it didn't rain too much, but it was overcast all day with a steady, biting wind; visibility good, only the very tops of the mountains were in the clouds. I considered it the authentic Welsh experience (except there was no fog).
It's called Snowdonia because of Snowdon, the highest mountain in Wales (and the highest in Britain south of Scotland), 3,560 feet. (Shut up, you Sierra hikers; I can hear you sniggering.) You can take a train up Snowdon, if you don't feel up to the hike, but the day we were there, it was only going about 3/4 of the way up (probably due to cloud cover) and would take almost 2 hours, so we passed. During the stop, however, I got what I think was my first lungful of coal smoke. When we went to New Zealand, we rode a coal-burning steamboat up Lake Wakatipu, by Queensland; but the motion of the boat meant the smoke was behind us. Coal smoke is brown and extremely smelly; I can't imaging how people could have used it for heating and cooking.
During this drive around, we stopped at two places that really could not be more different: Portmeirion, and Harlech Castle. I'll take Portmeirion first, because it's the oddest. (If any of you are fans of The Prisoner, you may already know this, because it was largely filmed there.)
Portmeirion is a largely Italianate village, an eclectic collection of generally Mediterranean styles with an equally eclectic collection of decorations (I don't think of Buddha as Italianate, but there's a Buddha statue), set down on a Welsh hillside overlooking an estuary off Tremadog Bay, on the Irish Sea. Portmeirion was built, over 50 years or so, by Sir Clough Williams-Ellis, who wanted to "demonstrate how a naturally beautiful site could be developed without spoiling it." I presume he didn't like stone buildings. He was over 90 when it was finally done. The buildings are set among elegant formal gardens, with classical statuary and a reflecting pool; there is also a band shell. The day we were there, the band was playing in the shell, while the rain came down outside; two people were sitting next to the pool listening, under a large umbrella. The buildings are all stuccoed, and painted various shades of pastel - yellow, turquoise blue, peach. The contrast with the rest of rural Wales, where I never saw a house that was any color other than stone, or whitewashed stucco, is staggering. (The "smallest house in Great Britain" was, in fact, painted red; but that's (a) in a town, and (b) a tourist stunt.) Portmeirion might come across as a charming Mediterranean village on a warm, sunny summer day; but we were there on a cold, overcast, windy summer day, and the whole place, as I heard another visitor say, was "surreal". God knows what it's like in winter. Since there isn't much to do there unless you want to worship at The Prisoner shrine, we walked around, had lunch, and went on to Harlech Castle.
Harlech Castle is the absolute antithesis of Portmeirion, although it's only about 5 miles away. Like Conwy Castle, Harlech was built by Edward I in the late 13th century, as part of his "iron ring" around Snowdonia, to contain the Welsh. The coastline has moved, but it was originally perched on a crag dropping straight into the sea; it was essentially impregnable from the land side, while it could be supplied by sea during a siege. Unlike Conwy Castle, Harlech has no remaining interior walls of any significance. There are excellent photographs at this site, but the day we were there, we didn't see the beautiful blue sky; it's actually more impressive on an overcast day. The visible walls are the original inner walls; the outer ring of fortifications didn't survive the next 400 years of warfare. A siege during the Wars of the Roses is said to have given rise to the song, Men of Harlech. The castle last saw action in the 17th century; it was the final Royalist stronghold to fall in the English Civil War. Harlech is an absolute classic of medieval military architecture and beautiful in a stern way.