A few years back i went to Banff Alberta Canada 😀 This mud goo pool is a hotspring, the smell or hmm stink 😉 is over overwhelming to say the leasts, I find it kind of cool though and did of course stick my nose into it, no not for the smell but to see if I could grab a good picture. There are nine different naturally occurring hot springs in the Banff area. The flow rates fluctuate seasonally with snow melt, with highest flows in the spring and lowest during winter.
Great photo