Minimum ARIA accessible menu.

gistfile1.html

<div role="navigation">
	<ul role="menubar" aria-label="Menu Bar">
		<li role="presentation" tabindex="0">
			<a href="item-1.html" role="menuitem" id="nav-item-1" aria-haspopup="true">Item 1</a>
			<ul role="menu" aria-expanded="false" aria-hidden="true" aria-labelledby="nav-item-1">
				<li role="presentation"><a href="item-1-1.html" role="menuitem">Item 1.1</a></li>
				<li role="presentation"><a href="item-1-2.html" role="menuitem">Item 1.2</a></li>
				<li role="presentation"><a href="item-1-3.html" role="menuitem">Item 1.3</a></li>
			</ul>
		</li>
		<li role="presentation"><a href="item-2.html" role="menuitem">Item 2</a></li>
		<li role="presentation">
			<a href="item-3.html" role="menuitem" id="nav-item-3" aria-haspopup="true">Item 3</a>
			<ul role="menu" aria-expanded="false" aria-hidden="true" aria-labelledby="nav-item-1">
				<li role="presentation"><a href="item-3-1.html" role="menuitem">Item 3.1</a></li>
				<li role="presentation"><a href="item-3-2.html" role="menuitem">Item 3.2</a></li>
				<li role="presentation">
					<a href="item-3-3.html" role="menuitem" id="nav-item-3-3" aria-haspopup="true">Item 3.3</a>
					<ul role="menu" aria-expanded="false" aria-hidden="true" aria-labelledby="nav-item-3-3">
						<li role="presentation"><a href="item-3-3-1.html" role="menuitem">Item 3.3.1</a></li>
						<li role="presentation"><a href="item-3-3-2.html" role="menuitem">Item 3.3.2</a></li>
						<li role="presentation"><a href="item-3-3-3.html" role="menuitem">Item 3.3.3</a></li>
					</ul>
				</li>
			</ul>
		</li>
	</ul>
</div>

Outermost div has a landmark role of navigation.

• Outermost ul has a role of menubar, an requires an aria-label.
• Submenu ul elements have a role of menu and an aria-labelledby referencing the preceeding sibling anchor ID.
• All list item elements have a presentation role only.
• All anchor elements have a role of menuitem.
• Anchors which lead to a submenu, have a true aria-haspopup.
• JavaScript should update aria-expanded / aria-hidden state attributes as required.