My son and I liked this one so much we did it twice, but the second time following a slightly greener path and stopping at Heiliger Stein just over the border instead of continuing on to Retz.
Znojmo to Retz: nice ride, can be hilly, but still quite do-able.
You pretty much have two option for getting there, either take the bike paths (path 5000) or go the paved roads (the 413/35).
On the way to Retz, we took the paved road because it was easier. On the return we took the bike paths and sometimes just asked around, which worked quite well.
Getting in and out of the city of Znojmo can be tricky. Again you seem to have only two options, either the very steep paths just below the castle or the paved roads that take you through Novy Saldorf. These roads are easy to follow and like most of our rides down here, incredibly well marked.
Worth notice is the pub in Konice, the “Pub at the Top of the Hill”, a good place to stop regardless of which direction you are going.
Just after, in the hills near Popice is a nice old, church “Poutni Kaple P. Marie Bolestne” (renovated) and a pump with great water to re-fill your water-bottles just next to it.
… and right after, a great wine stand where you can stop and sample Znovin Znojmo alongside the “Old Vinyards”.