Supongo ke lo querras para que al pulsar un boton aparezcan y desaparezcan como tu quieras no?
  Código PHP:
    <head>
<title>-- BEJAR --</title>
<link rel="stylesheet" type="text/css" href="estilos.css" />
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript" type="text/JavaScript">
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function MM_reloadPage(init) {  //reloads the window if Nav4 resized
  if (init==true) with (navigator) {if ((appName=="Netscape")&&(parseInt(appVersion)==4)) {
    document.MM_pgW=innerWidth; document.MM_pgH=innerHeight; onresize=MM_reloadPage; }}
  else if (innerWidth!=document.MM_pgW || innerHeight!=document.MM_pgH) location.reload();
}
MM_reloadPage(true);
 
function MM_findObj(n, d) { //v4.01
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    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
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  if(!x && d.getElementById) x=d.getElementById(n); return x;
}
 
function MM_showHideLayers() { //v6.0
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    if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v=='hide')?'hidden':v; }
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</script>
</head>
<body>
<div id="content">
    <div id="cabecera">
        <img src="imagenes/cabecera.jpg" alt="cabecera">
    </div> 
    <div id="menu">
        <div id="dolphincontainer">
            <div id="dolphinnav">
                <ul>
                    <li><a href="index.html" title="Bejar"><span>Bejar</span></a></li>
                    <li><a href="historia.html" title="Historia"><span>Historia</span></a></li>
                    <li><a href="monumentos.html" title="Monumentos" class="current"><span>Monumentos</span></a></li>
                    <li><a href="tradiciones.html" title="Traciciones"><span>Tradiciones</span></a></li>
                    <li><a href="local.html" title="Localización"><span>Localización</span></a></li>
                    <li><a href="alojamientos.html" title="Alojamientos"><span>Alojamientos</span></a></li>
                    <li><a href="imagenes.html" title="Imágenes"><span>Imágenes</span></a></li>
                </ul>
            </div>
        </div>
    </div>
    <div id="contenido_sin"> 
      <div id="menu_contenido">
        <br><br><br>
            <table border="0" align="center" width="150">
                <tr valign="top">
                    <td>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento2','','hide','monumento3','','hide','monumento4','','hide','monumento5','','hide','monumento6','','hide','monumento7','','hide','monumento1','','show')">
                            <img src="imagenes/mon1.jpg" border="0">
                        </a>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento1','','hide','monumento3','','hide','monumento4','','hide','monumento5','','hide','monumento6','','hide','monumento7','','hide','monumento2','','show')">
                            <img src="imagenes/mon2.jpg" border="0">
                        </a>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento1','','hide','monumento2','','hide','monumento4','','hide','monumento5','','hide','monumento6','','hide','monumento7','','hide','monumento3','','show')">
                            <img src="imagenes/mon3.jpg" border="0">
                        </a>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento1','','hide','monumento2','','hide','monumento3','','hide','monumento5','','hide','monumento6','','hide','monumento7','','hide','monumento4','','show')">
                            <img src="imagenes/mon4.jpg" border="0">
                        </a>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento1','','hide','monumento2','','hide','monumento3','','hide','monumento4','','hide','monumento6','','hide','monumento7','','hide','monumento5','','show')">
                            <img src="imagenes/mon5.jpg" border="0">
                        </a>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento1','','hide','monumento2','','hide','monumento3','','hide','monumento4','','hide','monumento5','','hide','monumento7','','hide','monumento6','','show')">
                            <img src="imagenes/mon6.jpg" border="0">    
                        </a>
                        <a href="javascript:;" onClick="MM_showHideLayers('general','','hide','monumento1','','hide','monumento2','','hide','monumento3','','hide','monumento4','','hide','monumento5','','hide','monumento6','','hide','monumento7','','show')">
                            <img src="imagenes/mon7.jpg" border="0">
                        </a>
                    </td>
                </tr>
            </table>
      </div>
        <div id="contenido_con">
            <div id="general" style="position:absolute;">
                <br>
                <div class="titulos1" align="center">MONUMENTOS</div>
                <br>
                <table border="0" width="560">  
                    <tr>
                        <td align="center">
                            <img src="imagenes/ayuntamiento.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Ayuntamiento
                        </td>
                        <td align="center">
                            <img src="imagenes/bosque.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Bosque
                        </td>
                        <td align="center">
                            <img src="imagenes/convento.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Convento de San Francisco
                        </td>
                    </tr>
                    <tr>
                        <td align="center">
                            <img src="imagenes/plazato.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Plaza de Toros
                        </td>
                        <td align="center">
                            <img src="imagenes/palacioducal1.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Palacio Ducal
                        </td>
                        <td align="center">
                            <img src="imagenes/teatro.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Teatro Cervantes
                        </td>
                    </tr>
                    <tr>
                        <td colspan="3" align="center">
                            <img src="imagenes/murallas.jpg" width="150" height="85" style=" border-style:ridge; border-color:#000000; border-width:thin; "><br>
                            Las Murallas
                        </td>
                    </tr>
                </table> 
            </div>
            <div id="monumento1" style="visibility:hidden; position:absolute;">
                <table width="560">
                <tr>
                <td>
                <br>
                <div class="titulos1" align="center">PALACIO DUCAL</div>
                </div>
                </td></tr></table>
            </div> 
   
  Espero te sirva. El resto de las capas no las pongo ppk son iguales jeje