An alternative way to link to external pages.

This is a Collections > Sorted Tile List page containing two Pages > External Pages 
In the Inspector for the External Page the Type of Link is set to Page within page: 100% width; 700 pixels height.

The 'Page within page' uses the iframe HTML tag but all the work is done by Sandvox and does not require you to edit the Raw HTML code of the page to use the effect. 

I don't see a way to add a description for each page this way as was done on the  post [List of Links].