It's kind of hard to distinguish the villages of Shirakawa-go and Gokayama in the postcards if they have nothing written. These historical villages are very look alike because of its typical houses.
This postcard was sent by Hiro
Shirakawa is a mountain village located at the highest peak on Mount Haku in the Ryōhaku Mountains, where it borders Ishikawa prefecture.
Shirakawa is a leading area of heavy snowfall in the world, and due to this climate, gasshō-zukuri (合掌造り) homes were created. Gassho-zukuri settlements are registered as cultural heritage sites. With the shape of the Hakusan National Park mountain ranges as a background, these sites are major tourist attractions. - in: wikipedia
This postcard was sent by Jennifer
Due to the income from the tourists who came to see the gassho-zukuri villages, the financial condition was greatly improved. Although the area was famous as a tourist site, once it became a UNESCO site, the area greatly grew as tourists visited. Although this success from tourism helped the income of the area, on the other hand, there was an outbreak of damage to the area from tourists entering people's homes to see how they lived, taking pictures and other such manners. in: wikipedia
This postcard was sent by Kazumi
Gokayama is an area within the city of Nanto in Toyama Prefecture, Japan. It has been inscribed on the UNESCO World Heritage List due to its traditional gasshō-zukuri houses, alongside nearby Shirakawa-gō in Gifu Prefecture. The survival of this traditional architectural style is attributed to the region's secluded location in the upper reaches of the Shōgawa river. This is also the reason that Gokayama's lifestyle and culture remained very traditional for many years after the majority of the country had modernized. Many of the houses easily surpass 300 years in age. - in: wikipedia