In all three spots, you could drill straight through and come up in a place where you might bump into the occasional seal and, in one place if you arrive at the right time of year, a scientist or two.

NPR: Dig a Hole to China? Try a Sandwich Instead

So if you are a packaged product fan and prefer ETFs to straight bonds, then you need to drill down into the ETF holdings.

FORBES: Juicy and Junky High Yield ETFs