### Clue: Old Vlad in the Netherlands climbing? Only it's flat! (5,4)
### Answer: LEMON SOLE 
 ### Explanation: Definition: it's flat
 **Reversal of**(… climbing, in a down clue) [ O(abbrev. for "old") + ME(Vlad, our setter using the self-referential pronoun) **contained in**(in) NL(ISO 3166 code for the Netherlands) ] + SOLE(the one and only).
Defn: …, a flat fish, that is.