Another magnificent Peruvian WHS! And I get to review it first! Hurray!
Childish crowing on my part aside, this is another excellent place to visit. The entry fees are cheap and good value as well.
Chan Chan is an amazing place, and is absolutely enormous. I believe that at one time it was the biggest city on the planet, but that would need to be checked.
To be honest, much of the site is in complete ruins and is nothing more than large piles of mud. However, the Tschudi Palace is being constantly restored and gives a wonderful idea of how magnificent this city must have been.
I'm no expert but the restoration work seems to be going along sensitively and successfully, and this is one site where it is a case of restore it as much as possible, or lose it completely. The El Nino effect has clearly caused a massive amount of damage to the site (and it finished off Chan Chan as a living city).
I do not know why it is on the 'in danger' list but I guess it is for two reasons. One is El Nino - this is a situation that will never change. The second is probably the vast amounts of refuse that seem to be piling up around the outside of the city itself. This is something that seriously needs to be addressed.
Visitors to Chan Chan should also check out the nearby Huaco De La Sol and Huaco De La Luna. An incredible site that definately should be on the WH list, and created more of an impact than Chan Chan.