Swiss heights (4)
I believe the answer is:
alps
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">swiss heights</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for alps that I've seen before include "South-central European mountain system" , "Slopes" , "Slap about in mountains" , "With pals in great mountains" , "Mountain system, highest peak Mont Blanc" .)