[The Duke of Norfolk] toil'd with works of war, retired himself
To Italy; and there at Venice gave
His body to that pleasant country's earth,
- Richard II IV,1
It's an odd thing that Shakespeare set a play and a bit in Venice (Merchant and Othello) and mentions the city 46 times*, but he doesn't seem to have realised that the city was built in the sea.
At least, that's the implication of the lines above. The Merchant of Venice contains not a solitary reference to gondolas or canals, and nor does Othello. As Holofernes says in Love's Labours Lost:
I may speak of thee as the traveller doth of Venice;
Chi non ti vede non ti pretia.
Which means Venice, Venice, he who has not seen you cannot appreciate you.
And that seems to have been the case with Will. To be fair, Venice in Shakespeare's time ruled a lot of territory on the mainland. This was known as terra firma, which is the origin of the phrase.
Anyway, how do you make a Venetian blind?
Poke his eyes out.
Shakespeare was never wrong, reality sometimes stumbled.
*58, if you count variants like Venetian.