diff --git a/web/wall.html b/web/wall.html
index a146131..5a2b6a4 100644
--- a/web/wall.html
+++ b/web/wall.html
@@ -581,6 +581,10 @@
       <label for="f-author">Autor / fotógrafo</label>
       <select id="f-author"><option value="">todos</option></select>
     </div>
+    <div class="f-row">
+      <label for="f-subject">Assunto</label>
+      <select id="f-subject"><option value="">todos</option></select>
+    </div>
     <div class="f-row">
       <label for="f-type">Tipo de suporte</label>
       <select id="f-type"><option value="">todos</option></select>
@@ -1399,9 +1403,14 @@ function cleanAuthor(raw) {
 // same person, different word order or accents → same key
 const authorKey = name => deburr(name).replace(/[^a-z0-9 ]/g, ' ').split(/\s+/).filter(Boolean).sort().join(' ');
 
+// dc.subject folds accents and case; the select shows only tags that recur, since
+// ~8000 distinct values (57% used once) would be an unusable list
+const subjectKey = t => deburr(String(t)).replace(/\s+/g, ' ').trim();
+const SUBJECT_MIN = 20;
+
 function setupFilters(mapData) {
   const entries = Object.values(mapData.map);
-  const instCounts = new Map(), typeCounts = new Map(), authorGroups = new Map();
+  const instCounts = new Map(), typeCounts = new Map(), authorGroups = new Map(), subjectGroups = new Map();
   let minYear = Infinity, maxYear = -Infinity;
 
   entries.forEach(e => {
@@ -1409,6 +1418,10 @@ function setupFilters(mapData) {
     if (meta.community) instCounts.set(meta.community, (instCounts.get(meta.community) || 0) + 1);
     const t = cleanType(meta.type);
     if (t) typeCounts.set(t, (typeCounts.get(t) || 0) + 1);
+    new Set([].concat(meta.subject || []).map(subjectKey)).forEach(k => {
+      if (!k) return;
+      subjectGroups.set(k, (subjectGroups.get(k) || 0) + 1);
+    });
     const a = cleanAuthor(meta.contributor);
     if (a) {
       const k = authorKey(a), g = authorGroups.get(k) || { n: 0, forms: new Map() };
@@ -1446,6 +1459,18 @@ function setupFilters(mapData) {
     selAuthor.appendChild(opt);
   });
 
+  const subjectNames = new Map(); // key → a readable spelling
+  entries.forEach(e => [].concat((e.meta || {}).subject || []).forEach(t => {
+    const k = subjectKey(t);
+    if (k && subjectGroups.get(k) >= SUBJECT_MIN && !subjectNames.has(k)) subjectNames.set(k, String(t).trim());
+  }));
+  const selSubject = document.getElementById('f-subject');
+  [...subjectGroups.entries()].filter(([, n]) => n >= SUBJECT_MIN).sort((a, b) => b[1] - a[1]).forEach(([k, n]) => {
+    const opt = document.createElement('option');
+    opt.value = k; opt.textContent = `${subjectNames.get(k)} (${n.toLocaleString('pt-BR')})`;
+    selSubject.appendChild(opt);
+  });
+
   const decadeMin = Math.floor(minYear / 10) * 10;
   const decadeMax = Math.floor(maxYear / 10) * 10;
   const nDecades = (decadeMax - decadeMin) / 10 + 1;
@@ -1477,6 +1502,7 @@ function setupFilters(mapData) {
     const a = cleanAuthor(meta.contributor);
     m.userData._author = a ? authorKey(a) : '';
     m.userData._type = cleanType(meta.type);
+    m.userData._subjects = new Set([].concat(meta.subject || []).map(subjectKey));
     // one haystack per piece: every metadata field, not a chosen few
     // the handle is the map's key, not a field of meta — it still has to be
     // searchable (people paste a handle or its number straight into the box)
@@ -1501,7 +1527,7 @@ function setupFilters(mapData) {
     bars.push(bar);
   }
 
-  const state = { search: '', institution: '', yearLo: decadeMin, yearHi: decadeMax, yearTouched: false, author: '', type: '' };
+  const state = { search: '', institution: '', yearLo: decadeMin, yearHi: decadeMax, yearTouched: false, author: '', type: '', subject: '' };
 
   function resetYear() {
     state.yearTouched = false;
@@ -1523,6 +1549,7 @@ function setupFilters(mapData) {
         (!state.institution || meta.community === state.institution) &&
         (!state.type || d._type === state.type) &&
         (!state.author || d._author === state.author) &&
+        (!state.subject || d._subjects.has(state.subject)) &&
         terms.every(t => d._hay.includes(t));
       if (okRest && d._year != null) {
         const i = Math.floor((d._year - decadeMin) / 10);
@@ -1583,6 +1610,7 @@ function setupFilters(mapData) {
     if (state.institution) out.push({ key: 'institution', text: state.institution });
     if (state.yearTouched) out.push({ key: 'year', text: yearLabel(state.yearLo, state.yearHi) });
     if (state.author) out.push({ key: 'author', text: authorNames.get(state.author) });
+    if (state.subject) out.push({ key: 'subject', text: subjectNames.get(state.subject) });
     if (state.type) out.push({ key: 'type', text: state.type });
     return out;
   }
@@ -1591,6 +1619,7 @@ function setupFilters(mapData) {
     if (key === 'search') { state.search = ''; searchInput.value = ''; }
     if (key === 'institution') { state.institution = ''; selInst.value = ''; }
     if (key === 'type') { state.type = ''; selType.value = ''; }
+    if (key === 'subject') { state.subject = ''; selSubject.value = ''; }
     if (key === 'author') { state.author = ''; selAuthor.value = ''; }
     if (key === 'year') resetYear();
     apply();
@@ -1632,6 +1661,7 @@ function setupFilters(mapData) {
   });
   searchX.addEventListener('click', () => { clearTimeout(searchTimer); clearOne('search'); searchInput.focus(); });
 
+  selSubject.addEventListener('change', () => { state.subject = selSubject.value; apply(); });
   selAuthor.addEventListener('change', () => { state.author = selAuthor.value; apply(); });
 
   function onYear(e) {
@@ -1651,8 +1681,8 @@ function setupFilters(mapData) {
 
   clearBtn.addEventListener('click', () => {
     clearTimeout(searchTimer);
-    state.search = ''; state.institution = ''; state.type = ''; state.author = '';
-    searchInput.value = ''; selInst.value = ''; selType.value = ''; selAuthor.value = '';
+    state.search = ''; state.institution = ''; state.type = ''; state.author = ''; state.subject = '';
+    searchInput.value = ''; selInst.value = ''; selType.value = ''; selAuthor.value = ''; selSubject.value = '';
     resetYear();
     apply();
   });