Your question was: 'Is this the Eperlecques Blockhouse?', followed by a link to..... Well, I guess you know where the link lead....

Now relax.
To answer your question: It's as interesting as a very large block of massive (partially smashed) concrete deep in a wood can be. Listen to the simple commentary at each of the listening posts to get a feel for what sort of mischief the Hun got up to, how difficult it was to actually hit the thing (despite its size) from the air and spare a thought for the army of mistreated slave labourers the Germans brought in to construct the project, build the support railways and not least the poor sods on whose heads the massive rockets fell. The other possibly interesting thing is the really quite successful subterfuge the Germans put in place to disguise the site's real purpose. Of course if nobody slaving on the site had ever seen a rocket, then it is incredibly difficult to imagine one.
In all there are three main V-weapon sites in the Pas de Calais region, but a host of very much smaller launch sites, most of which are lost to time, undergrowth or rebuilding.
The Eperlecques blockhouse, V2's only
La Coupole, V1's only. This is a much bigger museum than at the V2 site
The V3 'Super gun'. This is interesting in as much as the gun was the forerunner of the Iraq 'super gun' over which there was so much trouble a few years back.
http://www.theotherside.co.uk/tm-heritage/visit/visit-2caps-mimoyec-v3.htm
http://www.century-of-flight.net/Aviation history/WW2/v3.htm
There are assorted threads on UKGSer (pictures etc) on both the V1 and V2 sites, along with many independent pages on the web. Less about the V3 site.