Super Mario RRG Early Release Switch - Part 2 Onward to Tadpole Pond

We collect the First start (the Blue one)
and make short work of the 1st an 2nd bosses,
DOWN the waterfalls to the coin collecting mini game and safe at the bottom
I keep looking for those SECERT TREASURE BOXES with no luck.
It's been 10 years since i played this game, I forgot where they where.