{"version":"1.0","provider_name":"Castle Ruins &amp; Velvet Cave","provider_url":"https:\/\/www.kasteelvalkenburg.nl\/en\/","author_name":"James Robinson","author_url":"https:\/\/www.kasteelvalkenburg.nl\/en\/author\/james-robinson\/","title":"Velvet Cave - Castle Ruins &amp; Velvet Cave","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"5AcBsaIrfn\"><a href=\"https:\/\/www.kasteelvalkenburg.nl\/en\/discover-our-locations\/velvet-cave\/\">Velvet Cave<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.kasteelvalkenburg.nl\/en\/discover-our-locations\/velvet-cave\/embed\/#?secret=5AcBsaIrfn\" width=\"600\" height=\"338\" title=\"&#8220;Velvet Cave&#8221; &#8212; Castle Ruins &amp; Velvet Cave\" data-secret=\"5AcBsaIrfn\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script>\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n\/\/# sourceURL=https:\/\/www.kasteelvalkenburg.nl\/wp-includes\/js\/wp-embed.min.js\n<\/script>\n","thumbnail_url":"https:\/\/www.kasteelvalkenburg.nl\/wp-content\/uploads\/2020\/03\/Kasteelgrot-Fluweelengrot_Rondleiding-over-ons.jpg","thumbnail_width":1440,"thumbnail_height":662,"description":"Labyrint by mining Marl was mined from the cave by block breakers for use as a building stone in the construction of edifices like Valkenburg Castle. The result of this marlstone mining is an extensive labyrinth of old and rugged passageways. Tickets Secret passageways In times of siege, the secret passageways, which were only discovered [&hellip;]"}