They are in the Solcean Ruins in solcean town.
the simble pokemon, unknown.
The Unown are in the Solaceon Ruins.
you can catch a lot of unknown Pokemon A-Z
There are 26 but since there are the ! and ? unknown 28 total
To get a Venusaur on Pokemon Diamond you have to get the National Pokedex and look for its area, if it's unknown then I don't know what to do.
NO
right of solaceon town
turn back cave
Solceon ruins.
in the Solaceon Ruins.
You can find them in solaceon ruins
#114 is unknown. its found in the soleancean ruins