We’ll be crossing the equator on Monday night this week as we head out for our first ever visit to South America, arriving in Rio de Janeiro on Tuesday morning. Perhaps surprisingly this will be only our second ever foray across the equator, our one previous destination south of the line was our honeymoon trip to Tanzania and Zanzibar back in 2013. Given that Rio will be the furthest point south we have so far visited, our thoughts have turned inevitably to the extremities of our previous adventures. The furthest point north so far is St Petersburg, a beautiful and majestic city which we visited in the depths of its…