Errors:
Stray end tag “meta”.
A “charset” attribute on a “meta” element found after the first 1024 bytes.
A “meta” element with an “http-equiv” attribute whose value is “X-UA-Compatible” must have a “content” attribute with the value “IE=edge”.
Element “a” not allowed as child of element “ul” in this context. (Suppressing further errors from this subtree.)
Stray end tag “div”.
Duplicate ID “mainnav”.
Duplicate ID “mn-visit”.
Duplicate ID “mn-plan-your-visit”.
Duplicate ID “mn-exhibits”.
Duplicate ID “mn-around-town”.
Duplicate ID “mn-art-loft”.
Duplicate ID “mn-ideaworks”.
Duplicate ID “mn-kid-grid”.
Duplicate ID “mn-moneypalooza”.
Duplicate ID “mn-piece-out”.
Duplicate ID “mn-power2play”.
Duplicate ID “mn-seedlings”.
Duplicate ID “mn-splash”.
Duplicate ID “mn-stemosphere”.
Duplicate ID “mn-stepnotes”.
Duplicate ID “mn-sun-sprouts”.
Duplicate ID “mn-toddlers-hollow”.
Duplicate ID “mn-treetunes”.
Duplicate ID “mn-campus-map”.
Duplicate ID “mn-marbles-imax”.
Duplicate ID “mn-cafe”.
Duplicate ID “mn-marbles-corner-store”.
Duplicate ID “mn-access-and-inclusion”.
Duplicate ID “mn-access-programs”.
Duplicate ID “mn-gift-cards”.
Duplicate ID “mn-playtools”.
Duplicate ID “mn-become-a-member”.
Duplicate ID “mn-renew-a-membership”.
Duplicate ID “mn-gift-a-membership”.
Duplicate ID “mn-birthday-parties-facility-rentals”.
Duplicate ID “mn-birthday-parties”.
Duplicate ID “mn-corporate-events”.
Duplicate ID “mn-weddings-and-galas”.
Duplicate ID “mn-coming-up-redirect”.
Duplicate ID “mn-calendar”.
Duplicate ID “mn-events”.
Duplicate ID “mn-21marbles”.
Duplicate ID “mn-big-idea-forum”.
Duplicate ID “mn-bike-rodeo”.
Duplicate ID “mn-evening-with-elves”.
Duplicate ID “mn-family-fun-night”.
Duplicate ID “mn-future-me-kids-career-fair”.
Duplicate ID “mn-gingerbread-jamboree”.
Duplicate ID “mn-imagination-ball”.
Duplicate ID “mn-kick-off-to-kindergarten”.
Duplicate ID “mn-marbles-kooky-spooky-halloween-party”.
Duplicate ID “mn-princess-tea”.
Duplicate ID “mn-camps”.
Duplicate ID “mn-summer-camp”.
Duplicate ID “mn-schools-out-camps”.
Duplicate ID “mn-first-friday-kids-camp”.
Duplicate ID “mn-camp-ins”.
Duplicate ID “mn-classes-and-workshops”.
Duplicate ID “mn-educators”.
Duplicate ID “mn-field-trips”.
Duplicate ID “mn-prek”.
Duplicate ID “mn-pnc-playfree-access”.
Duplicate ID “mn-grades-k-3”.
Duplicate ID “mn-grades-4-5”.
Duplicate ID “mn-grades-6-8”.
Duplicate ID “mn-request-a-field-trip”.
Duplicate ID “mn-preparation-and-payments”.
Duplicate ID “mn-concessions”.
Duplicate ID “mn-field-trip-tool”.
Duplicate ID “mn-educator-events”.
Duplicate ID “mn-educator-advisory”.
Duplicate ID “mn-educator-resources”.
Duplicate ID “mn-get-involved”.
Duplicate ID “mn-donate_1”.
Duplicate ID “mn-individual-giving”.
Duplicate ID “mn-corporate-giving”.
Duplicate ID “mn-in-kind-donations”.
Duplicate ID “mn-our-donors”.
Duplicate ID “mn-volunteer”.
Duplicate ID “mn-individual-opportunities”.
Duplicate ID “mn-group-opportunities”.
Duplicate ID “mn-teen-play-corps”.
Duplicate ID “mn-big-kid-corps”.
Duplicate ID “mn-marblettes”.
Duplicate ID “mn-about-us”.
Duplicate ID “mn-history-mission”.
Duplicate ID “mn-blog”.
Duplicate ID “mn-Team-Marbles”.
Duplicate ID “mn-jobs”.
Duplicate ID “mn-news-and-media”.
Duplicate ID “mn-faqs”.
Duplicate ID “mn-membership_1”.
Duplicate ID “mn-contact-us”.
Duplicate ID “mn-imax”.
Attribute “rel” not allowed on element “b” at this point.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
Warnings:
The first occurrence of ID “mainnav” was here.
The first occurrence of ID “mn-visit” was here.
The first occurrence of ID “mn-plan-your-visit” was here.
The first occurrence of ID “mn-exhibits” was here.
The first occurrence of ID “mn-around-town” was here.
The first occurrence of ID “mn-art-loft” was here.
The first occurrence of ID “mn-ideaworks” was here.
The first occurrence of ID “mn-kid-grid” was here.
The first occurrence of ID “mn-moneypalooza” was here.
The first occurrence of ID “mn-piece-out” was here.
The first occurrence of ID “mn-power2play” was here.
The first occurrence of ID “mn-seedlings” was here.
The first occurrence of ID “mn-splash” was here.
The first occurrence of ID “mn-stemosphere” was here.
The first occurrence of ID “mn-stepnotes” was here.
The first occurrence of ID “mn-sun-sprouts” was here.
The first occurrence of ID “mn-toddlers-hollow” was here.
The first occurrence of ID “mn-treetunes” was here.
The first occurrence of ID “mn-campus-map” was here.
The first occurrence of ID “mn-marbles-imax” was here.
The first occurrence of ID “mn-cafe” was here.
The first occurrence of ID “mn-marbles-corner-store” was here.
The first occurrence of ID “mn-access-and-inclusion” was here.
The first occurrence of ID “mn-access-programs” was here.
The first occurrence of ID “mn-gift-cards” was here.
The first occurrence of ID “mn-playtools” was here.
The first occurrence of ID “mn-become-a-member” was here.
The first occurrence of ID “mn-renew-a-membership” was here.
The first occurrence of ID “mn-gift-a-membership” was here.
The first occurrence of ID “mn-birthday-parties-facility-rentals” was here.
The first occurrence of ID “mn-birthday-parties” was here.
The first occurrence of ID “mn-corporate-events” was here.
The first occurrence of ID “mn-weddings-and-galas” was here.
The first occurrence of ID “mn-coming-up-redirect” was here.
The first occurrence of ID “mn-calendar” was here.
The first occurrence of ID “mn-events” was here.
The first occurrence of ID “mn-21marbles” was here.
The first occurrence of ID “mn-big-idea-forum” was here.
The first occurrence of ID “mn-bike-rodeo” was here.
The first occurrence of ID “mn-evening-with-elves” was here.
The first occurrence of ID “mn-family-fun-night” was here.
The first occurrence of ID “mn-future-me-kids-career-fair” was here.
The first occurrence of ID “mn-gingerbread-jamboree” was here.
The first occurrence of ID “mn-imagination-ball” was here.
The first occurrence of ID “mn-kick-off-to-kindergarten” was here.
The first occurrence of ID “mn-marbles-kooky-spooky-halloween-party” was here.
The first occurrence of ID “mn-princess-tea” was here.
The first occurrence of ID “mn-camps” was here.
The first occurrence of ID “mn-summer-camp” was here.
The first occurrence of ID “mn-schools-out-camps” was here.
The first occurrence of ID “mn-first-friday-kids-camp” was here.
The first occurrence of ID “mn-camp-ins” was here.
The first occurrence of ID “mn-classes-and-workshops” was here.
The first occurrence of ID “mn-educators” was here.
The first occurrence of ID “mn-field-trips” was here.
The first occurrence of ID “mn-prek” was here.
The first occurrence of ID “mn-pnc-playfree-access” was here.
The first occurrence of ID “mn-grades-k-3” was here.
The first occurrence of ID “mn-grades-4-5” was here.
The first occurrence of ID “mn-grades-6-8” was here.
The first occurrence of ID “mn-request-a-field-trip” was here.
The first occurrence of ID “mn-preparation-and-payments” was here.
The first occurrence of ID “mn-concessions” was here.
The first occurrence of ID “mn-field-trip-tool” was here.
The first occurrence of ID “mn-educator-events” was here.
The first occurrence of ID “mn-educator-advisory” was here.
The first occurrence of ID “mn-educator-resources” was here.
The first occurrence of ID “mn-get-involved” was here.
The first occurrence of ID “mn-donate_1” was here.
The first occurrence of ID “mn-individual-giving” was here.
The first occurrence of ID “mn-corporate-giving” was here.
The first occurrence of ID “mn-in-kind-donations” was here.
The first occurrence of ID “mn-our-donors” was here.
The first occurrence of ID “mn-volunteer” was here.
The first occurrence of ID “mn-individual-opportunities” was here.
The first occurrence of ID “mn-group-opportunities” was here.
The first occurrence of ID “mn-teen-play-corps” was here.
The first occurrence of ID “mn-big-kid-corps” was here.
The first occurrence of ID “mn-marblettes” was here.
The first occurrence of ID “mn-about-us” was here.
The first occurrence of ID “mn-history-mission” was here.
The first occurrence of ID “mn-blog” was here.
The first occurrence of ID “mn-Team-Marbles” was here.
The first occurrence of ID “mn-jobs” was here.
The first occurrence of ID “mn-news-and-media” was here.
The first occurrence of ID “mn-faqs” was here.
The first occurrence of ID “mn-membership_1” was here.
The first occurrence of ID “mn-contact-us” was here.
The first occurrence of ID “mn-imax” was here.
Consider using the “h1” element as a top-level heading only (all “h1” elements are treated as top-level headings by many screen readers and other tools).
United States US