Nice cards guys! Thanks for posting them.
Here is a slightly different and earlier one. This is a German, 5 pf postal card to which a vignette has been added. The basic card is Michel #P12B. The small number"584" is printed on the bottom right of the address side of the card, signifying that this is from the batch of cards printed in May of 1884. Cancel is Ruedesheim 10 August 84. The picture on the back of the card is the National Monument in Niederwalde.
I believe this is Germany printed to private order postal card #PP6, of which there are several types. Presently, there is an 1888 card with a slightly different view of the Monument for sale on eBay
Germany. Apparently the cards were sold to tourists/visitors over a period of years.
From wikipedia, "The Niederwalddenkmal is a monument located in Niederwald, near Ruedisheim am Rhein in Hesse, Germany. Built between 1871 and 1883 to commemorate the unification of Germany, the monument is located within the Rhine Gorge, a larger UNESCO World Heritage site.."
Color pic is friom wikipedia.