The domain wikipedia.es was registered by BOOM BUSINESS, S.L a long time ago (2005-12-07). They made wikipedia.es redirect to the page http://mundo.es/.
We discussed that issue internally in WM-ES several times (trademarks, cybersquatters, NIC rules/DRP and taxes…), the last mention to that domain being in January 2015. Then, an hour ago, chatting in #wikimedia-operations about cybersquatters of wikipedia domains, and wanting to mention this case, I performed a whois on that domain, and discovered to my surprise that it now appears as owned by WMF! Although it's still redirecting to that unrelated page.
I have been unable to find any data about this transfer (wikitech, phabricator, meta, wikitech-l, foundation-l…), nor has the relevant chapter (WM-ES) been informed of this domain ownership change AFAIK. That's something to improve for the future IMHO.
In the technical side, the domain nameservers should be changed so the wmf domain no longer leads to the previous owner server. wikipedia.es should be a portal page leading to different wikipedias. The domain could be transfered to Wikimedia Spain, or -much easier- simply host the domain in WMF dns and create a couple of A entries to WM-ES server (188.8.131.52 - servidor.wikimedia.es).
I just added a brief portal at such vhost, so albeit perhaps not extremely pretty, pointing the domain there will work™