Wow - 21,000 is a lot of extra people to fit into our little city. But bring it on, I say.
The Lions tour is just weeks away, with the side and their huge army of supporters due to arrive in Rotorua for a match against the Maori All Blacks on Saturday, June 17.
I wasn't here for the 2005 Lions tour, but by all accounts it was an exciting time in Rotorua. And this year is expected to be even bigger.
With Rotorua having so much to offer visitors, aside from the rugby, it's likely many will spend more than just the one night in town. Accommodation providers, restaurant and bar owners and retailers will be rubbing their hands together in glee in anticipation of what is bound to be one of their biggest couple of days in years.
Even if you are not a rugby fan, there will be no escaping the fans in and around Rotorua.